Free Nutrition Tool
Find your resting metabolic rate and total daily calorie burn. Uses Mifflin-St Jeor by default and auto-switches to the leaner-mass Katch-McArdle equation when you enter body fat %. Then pick an activity level for your true daily energy needs.
Enter body fat % to switch to the Katch-McArdle equation (lean-mass based).
RMR (resting metabolic rate) is the energy your body needs at rest — breathing, circulation, cell repair. It's practically interchangeable with BMR for everyday use. TDEE is RMR multiplied by an activity factor (1.2–1.9) and represents your real daily calorie burn including movement and training.
By default we use Mifflin-St Jeor, the most accurate general equation: men = (10 × kg) + (6.25 × cm) − (5 × age) + 5; women subtract 161 instead of adding 5. If you enter body fat %, we switch to Katch-McArdle = 370 + 21.6 × lean body mass (kg), which accounts for how much muscle you carry and is often more accurate for lean or muscular individuals.
For fat loss, a moderate deficit of ~300–500 kcal below TDEE is sustainable. For muscle gain, a small surplus of ~150–300 kcal. These are starting points — track your weight for 2–3 weeks and adjust. Your body's real response beats any formula.
Estimates only; individual metabolism varies. Not medical or dietary advice. — Coach Scharnick, CSCS · B.S. Exercise Science